Pttlverized-ftjel feedeb



L. S. SCHMIDT.

PULVERIZED FUEL FEEDER.

APPLICATION FILED MAY 11. 1917.

Patented June 1, 1920. E

2 SHEETSSHEET 1.

L. S. SCHMIDT.

PULVERIZED FUEL-FEEDER.

APPLICATION FILED MAY n. l9l7.

2 SHEETS-SHEET 2.

FIBHE.

UNITED STATES PATENT OFFICE.

ZPULVERIZED-FUEL FEEDER.

Application filed May 11,

To all whom it may concern:

' Be it known that I, LAWRENCE S. SCHMIDT, a citizen of the UnitedStates, residing at Pittsbur h, in the county of Allegheny and State ofFennsylvania, have invented certain new and useful Im rovements inPulverized-Fuel Feeders, 0 which the following is a specification. I

' The prime objects of the present invention are to provide a new andimproved-pulverized fuel burner of simple and efficient con struction;new and improved fuel feed means whereb a greater feeding force is1mparted to t e fuel than has heretofore been possible; and means foreffecting a thorough atomization of the fuel.

With these objects and others in view, my invention is embodied inpreferable form in the constructions and'arrangements hereinafterdescribed and illustrated in the accompanying drawings.

In these drawings,

Figure 1 is a vertical section of the feedin structure and mechanism ofthe burner.

Fig. 2 is a detail section on the line 22 of Fig. 1.

Fig. 3 is an edge view of the air pressure element illustrated in Fig.2.

Fig. 4 is a section on the line 44 of Fig. 1.

ig. 5 is a vertical section of a modified form of the inventionemploying a positively driven impeller element in connection with asource of low pressure air.

Fig. 6 is a detail front elevation of the impeller element shown in Fig.5

I ig. 7 is a detail edge view of the element shown in Fig. 6.

Fig. 8 is a vertical section of another modified form of the apparatusshowing the combination of a source of low pressure air with a combinedpropeller and impeller element driven by a current of high pressure air.

Referring to the drawings and first to the construction illustrated inFigs. 1 to 4 inclusive, 1 is a bin adapted to contain the coal dust,powdered coal or prepared pulverized coal and which communicates with asubstantially vertical gravity-feed fuel conduit pipe 2 in which ismounted a valve 3 adapted to control the supply of fuel. The pipe 2communicates with a casing 4 preferably forming part of the main burnerstructure and this casing is prolonged laterally and horizontally toprovide a vacuum cham- Specification of Letters Patent.

Patented June 1, 1920.

1917. Serial No. 167,897.

ber 5 adjacent the inner horizontal end of the casing, and fuelpassageways 6 are provided between the outer wall of this casing and thewall of a conoidal body providing a chamber 7, these walls beingconnected by webs 8. chamber of a nozzle 9 which communicates at itsouter end with a burner (not shown). The chamber 7 communicates at itsouter end with a lon itudinal passageway 10 in which 18 mounted a pipe11 adapted to communi' cate with a source of high pressure air, such asa compression and impeller pump of the turbine type and which is notherein shown. The inner end of the chamber 7 is provided with a head 12through which extend longitudinally a series of small apertures 13, bymeans of which the air passes from the chamber to the nozzle, inparallelism to the fuel through the passageways 6.

The passageways 6 lead to the Mounted in the nozzle just beyond the headof the chamber and over the fuel outlets is a freely rotatably mountedcombined propeller and impeller member 14 which is carried loosely onthe bolt 15 fixed to the head 12. This member is preferably of the typeshown in Figs. 2 and 3 which illustrates a rotor having both propellerand impeller elements and operating on the turbine principle and inwhich'16 is an inner series of turbine blades adapted to receive thehigh pressure air from the chamber 7 whereby the member is driven andwhich is provided with an outer concentric series of turbine blades 17which constitute impeller elements and which act to create a vacuumadjacent the fuel outlets.and in the space 5' which would be produced bythe mere draft I of the current of air past the fuel.

In the operation of the device shown in Figs. 1 to 4 inclusive, the fuelis fed down the pipe 2 and air under high pressure is admitted to thechamber 7 whence it passes through the small passageways '13 and strikesaxially against the inner blades 16 of the air pressure member 14revolving said member in a high rate of speed and creating a vacuum inthe chamber 5 immediately adjacent said member which will have theeffect of sucking in the fuel with great violence through the opening 6into the chamber of the nozzle in which theair and fuel will bethoroughly commingled and the fuel pulverized into fine particles whichwill be effectively carried along by the stream of air, through thenozzle and toward. the burner. The rotary member 1% will also serve tomechanically disintegrate and scatter the fuel.

It will be seen that this arrangement provides a vacuum creating;-device within the nozzle and imi'i'iediately adjacent the junction ofthe fe d pipe with the nozzle. whereby a powerful. suction anddisintegrating action is exerted upon the air and fuel, as distinguishedfrom appzuratus in which a natural. draft or a forced draft from a.pressure device loaded at a distai'ice from said junction of the fueland air, is provided.

In. Figs. 5 to '7 inclusive. a construction is shown in which the vacuumcreating: element is shown as used in connection with a source of lowpressure air. ln this arrangement the said element is provided withimpeller blades only and is adapted to be positively driven bymechanical means from. an external source of power. in order to producethe necessary pressure for the creation of the vacuum in the adjacentend of the feed chamber.

Referring; to this construction. 18 is the conduit for the low pressureair which may be conducted by natural draft from the atmosphere or fromair heating; apparatus or a non-compressing fan. This low pressure airleads directly into the nozzle through a connecting elbow pipe section19. 20 is the nozzle. Formed in the elbow itting' 19 is a fuel receivingcasing 2i with which communicates the lower end of a fuel pipe 22.Passageways 23 lead from the chamber 21. into the nozzle. A conoidalbody 2 corre sponding to the body 7. coi'istitutiim' the air chamber inthe device of l ies. 1 to 4;. is formed in the casing 21. and in thisbody and in the wall of the casing is mounted a driving shaft which isadapted to be suitably connected to positively drivingmechanical. meansat its outer end and which at its inner end withii'i the nozzle andadiacent the fuel ()DQHlHQ'S 23 is provided with a driven member 26having): impeller elements 27.

In the operation of the device of 5 to 7 incli'isive. the low pressureair enters tl'irougl'i the pipe '18 and elbow l9 and thence passes intothe nozzle and the fuel is fed down the pipe into the chamber 91. Theimpeller element being positively driven from the source of externalpower creates a vacuum in the feed chamber 21 which will produce astrong suction feed on the fuel and a powerful disintegrating: andscattering action thereon.

It will be seen that the general form of the structural parts of theapparatus of Figs. 5 to 7 inclusive. corresponds to that of theapparatus of Figs. it to. 4. Thus for retains the high pressure air pipell inserted in the opening 10 in the casing of the latter construction,the shaft 25 of Figs. 5 to 7 inclusive is employed in connection withthe same structure of casing. To some extent, therefore, the parts areinterchangeable.

in Fig. 8, a. coni-itruction is shown in which the combined propellerand impeller vacuunji creating member of flip. l is illustrated. inconjunction with a source of low pressure air and in which such men'iberis adapted to be driv 11 by high. pressure air as in Iiig. .1, insteadof by a. pisitive drive from an external source of mechanical power asin l iu'. rangement, 28 is the fuel pipe. 29 the fuel feed chamber .inthe casing fUlll'llllQ part of the feeder structure, 30 an air chambercon'in'iunicatingi with a high pressure air pipe 3i and 32 a lowpressure pipe com municating with the nozzle 513. at the end of thechamber 29 and over the fuel openings Set and the air openings 85 isrotatably mounted the combined propeller and impeller air member 36which is of the double turbine type having two series of blade elements,as illustrated in Figs. 2 and 3. This member is adapted to be driven bythe high pressure air coming through the pipe 31, to thereby create asuction on the chamber to which the fuel. is fed. The main body of airsupply for mixing with the fuel is obtained through the low pressure airpipe.

What I claim is 1. In means for feeding pulverized. fuel, thecombination with a source of fuel supply, a casing having a closureprovided with a fuel outlet passage, a nozzle in advance of the closure,an air supply pipe in commimication with the nozzle. a rotor memberdisposed in advance of and adjacent the closure said rotor member havingimpeller means for creating a vaciiuim to exert a suction upon the fuelwithin the casing.

2. In means for feeding pulverized fuel. the combination. with source offuel supply a casing having a head provided with a fuel outlet passage anozzle in advance of the head. an air supply pipe in communicm tion withthe nozzle. a rotor member secured to the head, said rotor member havingimpeller means for creating a vaciuun to exert a suctionupon the fuelwithin the casing.

3. In means for coding pulverized fuel, the crm'ibination with a sourceof fuel. sup ply. casing having means to form an interior chamber, and aclosure for the casing; provided with a fuel outlet passage, a nozzle inadvance of tile closure an air supply pipe in communication with. thenozzle, a rotor member disposed adj acent the closure, said rotor memberhaving impeller means for creating a vacuum to exert a suction upon thefuel within the casing.

:1. In means for feeding pulverized fuel In this ar- 0 the combinationwith a source of fuel supply, a casing having means to form an interiorchamber from which the fuel is excluded, and a closure for the casingprovided with a fuel outlet passage and a passage in communi ration withthe interior chamber, a nozzle, an air supply pipe in connnunicationwith the nozzle, a rotor member disposed adjacent the closure, saidrotor member having impeller means for creating a vacuum to exert asuction upon the fuel within the casing.

5. In means for feeding fine coal, a fuel supply pipe, an air supplypipe, a casing having a head provided with independent outlet passagesfor fuel and air, a nozzle having a common chamber with which theoutlets communicate and a rotary member of the turbine type havingpropeller and impeller means mounted beyond the outlets.

6. In means for feeding fine coal, the combination with a fuel supplypipe, an air supply pipe adapted to supply air to mix with the coal, arotor member having propeller and impeller blades concentricallyarranged, said member mounted in advance of and adjacent to the fueloutlet, and means for driving said member by air under high pressure.

7. In means for feeding fine coal, in combination with a fuel pipe, anair supply pipe,

source of high pressure air and having air outlets leading to the nozzleand a combined propeller and impeller member mounted in the nozzlebeyond the fuel and air outlets and adapted to receive the pressure ofthe stream of air and to create a vacuum on the fuel outlets.

8. In means for feeding fine coal, in combination with a fuel supplypipe, an air supply pipe in communication with a source of low pressureair, a mixing chamber with which the outlets of said air pipe and fuelpipe communicate, a combined propeller and impeller member locatedadjacent the fuel outlet and adapted to create a vacuum to maintain asuction on the fuel and a source of high pressure air in communicationwith said member to drive the same.

In testimony whereof I aflix my signature in presence of two Witnesses.

LAWRENCE S. SCHMIDT.

WVitnesses:

W. G. DOOLITTLE, J. M. GEOHEGAN.

